Systems and Methods for a Conditioned Air Vestibule

ABSTRACT

A conditioned air vestibule can be positioned between a first zone and a second zone. The conditioned air vestibule can include a frame having first and second lateral side walls, a header positioned at the top of the frame, a blower, and an air flow assembly. The air flow assembly can include an exhaust panel having a plurality of exhaust ports. The plurality of exhaust ports can be in fluid communication with an interior of the frame and can provide a variable flow capacity that increases along a height of the exhaust panel from a top of the frame toward a bottom of the frame.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 63/350,637, filed Jun. 9, 2022, which is hereby incorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

The present disclosure is generally related to vestibules and doorway areas between differing conditioned air zones. For example, the present disclosure relates to vestibules used in cold storage doorways that can be used to control frost and ice buildup.

BACKGROUND

Vestibules configured as intermediate doorways or passageways between differing conditioned air zones, such as between a room temperature environment and a cold storage area, for example, can be subject to condensation, frost, and ice buildup. Such passageways between relatively warmer and colder zones can be used in commercial and industrial cold storage areas and may experience a natural exchange of air due to a difference in static pressure of warm air in the warmer zone and cold air in the colder zone. In particular, the denser cold air can infiltrate the warm zone near the bottom of the passageway, and correspondingly, the less dense warm air can infiltrate the cold zone near the top of the passageway. The cold air that permeates the bottom of the passageway can cool the ground and permit ice to form at the floor of the passageway. In addition, the warmer humid air that permeates the top of the passageway can become saturated or supersaturated and form frost and ice crystals on, for instance, cooler surfaces.

In general, ice that forms at the floor of a passageway between cold and warm zones can create a hazard to pedestrians, vehicles, and other machines that traverse the passageway. Additionally, when frost and ice crystals form as a result of, for instance, saturated or supersaturated air within and around the passageway, excessive and unwanted ice buildup can occur. Ice buildup can occur on nearby walls and refrigerator coils, which can cause the refrigeration system to require extra energy to keep the cold area chilled to a desired temperature.

Therefore, in view of at least the above, a need exists for a system and method for reducing interactions between conditioned zones (e.g., a warmer zone and a colder zone) separated by a conditioned air vestibule to inhibit, for instance, frost and ice formation or buildup.

SUMMARY

In many applications, it may be useful to efficiently condition air within a vestibule or passageway that extends between cold and warm zones to minimize or eliminate frost and ice buildup within or adjacent to the vestibule or passageway. For example, it may be useful to supply a dispersion of warm air (e.g., above the freezing temperature of water) within the vestibule or passageway, with increased airflow near the base of the vestibule or the ground of the passageway, to eliminate ice and reduce slipping hazards between the cold and warm zones. Additionally, it may be useful to eliminate or reduce frost buildup in and around the cold zone to lessen the energy expended to cool the cold zone and decrease the amount of work required to overcome the insulation provided by the ice buildup.

Some embodiments of the invention can provide a conditioned air vestibule configured to be positioned between a first zone (e.g., a warm zone) and a second zone (e.g., a cold zone). The vestibule can include a frame and a header, the header positioned at a top of the frame. The frame can extend between first and second lateral side walls. The vestibule can also include a blower and an airflow assembly. The airflow assembly can include an exhaust panel with a plurality of exhaust ports. The plurality of exhaust ports can be in fluid communication with an interior of the vestibule and can increase in flow capacity (e.g., greater density and/or increased size) along the length of the exhaust panel from proximate the top of the frame toward a bottom of the frame. An air passage can be in fluid communication with an outlet of the blower and the airflow assembly.

Some embodiments of the invention can provide an airflow assembly for a conditioned air vestibule. The airflow assembly can include an exterior frame member, a bottom plate, an exhaust panel, and an air passage. The exhaust panel can be configured to be secured relative to the exterior frame member. The air passage can be formed between the exterior frame member, the bottom plate, and the exhaust panel. The exhaust panel can include an exhaust port structured to provide increasing fluid communication along the exhaust panel between the air passage and an interior of the conditioned air vestibule.

Some embodiments of the invention provide a method of conditioning air in a vestibule positioned between first and second zones capable of different ambient conditions. The method can include intaking air from an interior of the vestibule into a header of the vestibule, conditioning the air, forcing the conditioned air through an air passage, and exhausting the conditioned air through an exhaust port formed in an exhaust panel and in fluid communication with the air passageway. The exhaust port can define an increasing air flow capacity from an upper end toward a lower end.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of embodiments of the invention:

FIG. 1 is an isometric view of a conditioned air vestibule according to an embodiment of the invention.

FIG. 2 is a front view of the vestibule of FIG. 1 .

FIG. 3 is an exploded isometric view of an airflow assembly of the vestibule of FIG. 1 .

FIG. 4 is an isometric view of the airflow assembly of FIG. 3 .

FIG. 5 is an isometric view of a header of the vestibule of FIG. 1 .

FIG. 6 is a cross-sectional isometric view of the header of FIG. 5 taken along line 6-6.

FIG. 7 is an exploded isometric view of the header of FIG. 5 .

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Given the benefit of this disclosure, various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention.

As used herein, unless otherwise defined or limited, directional terms are used for convenience of reference for discussion of particular figures or examples. For example, references to downward (or other) directions or top (or other) positions may be used to discuss aspects of a particular example or figure, but do not necessarily require similar orientation or geometry in all installations or configurations.

Also as used herein, unless otherwise limited or defined, “substantially parallel” indicates a direction that is within +12 degrees of a reference direction (e.g., within +6 degrees), inclusive. For a path that is not linear, the path can be considered to be substantially parallel to a reference direction if a straight line between end-points of the path is substantially parallel to the reference direction or a mean derivative of the path within a common reference frame as the reference direction is substantially parallel to the reference direction.

Also as used herein, unless otherwise limited or defined, “substantially perpendicular” indicates a direction that is within +12 degrees of perpendicular a reference direction (e.g., within +6 degrees), inclusive. For a path that is not linear, the path can be considered to be substantially perpendicular to a reference direction if a straight line between end-points of the path is substantially perpendicular to the reference direction or a mean derivative of the path within a common reference frame as the reference direction is substantially perpendicular to the reference direction.

Also as used herein, unless otherwise limited or defined, “integral” and derivatives thereof (e.g., “integrally”) describe elements that are manufactured as a single piece without fasteners, adhesive, or the like to secure separate components together. For example, an element stamped, cast, or otherwise molded as a single-piece component from a single piece of sheet metal or using a single mold, without rivets, screws, or adhesive to hold separately formed pieces together is an integral (and integrally formed) element. In contrast, an element formed from multiple pieces that are separately formed initially then later connected together, is not an integral (or integrally formed) element.

Additionally, unless otherwise specified or limited, the terms “about” and “approximately,” as used herein with respect to a reference value, refer to variations from the reference value of +15% or less, inclusive of the endpoints of the range. Similarly, the term “substantially equal” (and the like) as used herein with respect to a reference value refers to variations from the reference value of less than +30%, inclusive. Where specified, “substantially” can indicate in particular a variation in one numerical direction relative to a reference value. For example, “substantially less” than a reference value (and the like) indicates a value that is reduced from the reference value by 30% or more, and “substantially more” than a reference value (and the like) indicates a value that is increased from the reference value by 30% or more.

Also as used herein, unless otherwise limited or specified, “substantially identical” refers to two or more components or systems that are manufactured or used according to the same process and specification, with variation between the components or systems that are within the limitations of acceptable tolerances for the relevant process and specification. For example, two components can be considered to be substantially identical if the components are manufactured according to the same standardized manufacturing steps, with the same materials, and within the same acceptable dimensional tolerances (e.g., as specified for a particular process or product).

Throughout the disclosure, reference may be made to a warm(er) area (or zone) and a cold(er) area (or zone) without reference to specific temperatures. It should be appreciated that the use of warm and cold may be completely relative within the context of the warm and cold zones and that reference to a temperature of a warm zone only need be warmer than a temperature of a cold zone within the context of the given description. For example, in some contexts, while a refrigerated zone (e.g., at 3 degrees Celsius) may be considered a cold zone, it may also be considered a warm zone in the context of a refrigerator and a freezer (e.g., at −15 degrees Celsius). Additionally, as another example, a warm zone described herein may constitute a zone at room temperature (e.g., 20 degrees Celsius).

As briefly described above, vestibules and other intermediate passageways between warm areas and cold areas can be subject to unwanted condensation, deposition, frost, and ice buildup. In general, frost and ice buildup can be a result of natural or forced air exchange between air from each of the cold and warm zones. In particular, during the exchange, the denser cold air can infiltrate the warm area near the bottom of the passageway, and correspondingly, the less dense warm air can infiltrate the cold area near the top of the passageway. The cold air at the bottom of the passageway can cool the ground and promote unwanted ice formation near or at the floor. In addition, the warmer humid air near or at the top of the passageway can become supersaturated and promote the unwanted formation of ice crystals in the passageway and along the walls and/or coils of the cold area.

In some instances, vestibules and intermediate passageways between warm areas and cold areas, as described above, can be used in commercial and industrial applications. For example, such a vestibule or intermediate passageway may be disposed at an entrance to a cold storage zone or walk-in refrigeration/freezer area. In general, when liquid water or ice develops or is deposited in the passageway, it can create a hazard to people and machines, as well as subject personnel, product, tools, machinery, etc. to unwanted moisture and ice crystals.

In some conventional vestibules and doorways into cold areas (e.g., cold storage), a solid door may be used to provide a physical barrier between the warm and cold areas. In some instances, the door may be insulated and can prevent unwanted air distribution and infiltration between the zones of different temperature when the door is closed. However, when the door is open (either partially or fully to permit access between the areas to retrieve or store chilled materials, for example), the unwanted air infiltration resumes. Additionally, the opening and closing of the solid door can hinder the entry and exit of personnel and vehicles to the cold (or warm) area, which can cause a significant reduction in productivity.

In some conventional vestibules or doorways, other physical barriers may be used to reduce unwanted air distribution and infiltration between warm and cold zones. For example, such barriers can include hanging strips (e.g., vinyl strips) that are suspended from a header of a doorway, such as a strip curtain, and disposed between the warm and cold zones. A strip curtain may be used in place of a solid door in an effort lessen the negative impact to productivity and provide quicker maneuvering between zones. However, a strip curtain is less efficient than a solid door at insulating the passageway or vestibule between the zones and can still permit air infiltration, and thus frost and ice. Additionally, strip curtains can separate, deform, and/or degrade over time, which can allow additional air infiltration, thus further subjecting the passageway to, for instance, frost and ice formation and buildup.

Embodiments of the disclosed invention can address these and other drawbacks associated with conventional vestibules or doorways disposed between a warm zone and a cold zone. In particular, embodiments of the present invention provide systems and methods of preventing or reducing air infiltration at a vestibule or doorway between two different temperature zones. The two different temperatures zones, in some examples, may include one zone that is below freezing. Additionally, some embodiments of the invention provide systems and methods of preventing frost and ice buildup on a floor of a vestibule or doorway.

In some embodiments, a conditioned air vestibule system to inhibit air infiltration can include a vestibule frame that creates a space adjacent to an opening between two different temperature zones. The system can include a flexible barrier on each side of the vestibule frame adjacent to each corresponding opening to the two different temperature zones. The vestibule frame can additionally or alternatively include an air passage disposed within a header of the vestibule frame, the air passage continuing down each of the lateral sides of the vestibule frame between each opening to the two different temperature zones. A heater and blower assembly can be disposed at (e.g., housed within) the header and configured to draw air from the vestibule to heat the air and exhaust the air back into the vestibule via the air passage in the lateral side walls. The exhaust vents are disposed along the lateral side walls, are in fluid communication with the air passage, and progressively increase in open area from top to bottom to create a substantially even airflow in the vestibule to minimize and/or eliminate frost and ice buildup.

A blower and heater assembly may be advantageously disposed at the top of a vestibule frame (e.g., within a header) to collect less dense, warmer air that can be heated and sent through lateral side walls of the vestibule frame to heat an area within the vestibule frame and prevent ice formation therein and adjacent to the conditioned air vestibule. In other embodiments, a blower and/or heater assembly may be disposed at or within other parts of a vestibule frame, such as within the lateral sidewalls or the floor of the vestibule. However, it should be appreciated that positioning a blower or heater assembly at the top of a vestibule frame can promote increased energy efficiency and reduce the work required by the blower to heat the exhausted air sufficiently to keep ice from forming within the vestibule.

Referring now to FIG. 1 , a vestibule frame 100 of an example conditioned air vestibule 102 according to an embodiment of the invention is shown. In some embodiments, the vestibule 102 may be configured as a heated vestibule. The vestibule frame 100 includes first and second lateral side walls 104 and a header 106 disposed at a top 108 of the vestibule frame 100. The vestibule frame 100 can further define a floor (not shown) of the vestibule 102 at a bottom 110 of the vestibule frame 100. In general, the top 108 and bottom 110 of the vestibule orientationally correspond to the direction of gravity. That is, the direction of gravitational force is directed from the top 108 toward the bottom 110.

With continued reference to FIG. 1 , the vestibule frame 100 can further include first and second openings 112 (e.g., a front and back entrance/exit) that are flanked by the first and second lateral side walls 104. In the illustrated embodiment, only the first opening 112 of the two openings is fully shown, with the second opening 112 being offset from the first opening 112. In use, one opening may face a cold zone (e.g., a walk-in freezer, an outside of a building, etc.) and the other opening may face a warm zone (e.g., a warehouse, an inside of a building, etc.), however, other configurations are possible. In general, the vestibule 102 can provide a passageway (e.g., doorway) between different zones.

Still referring to FIG. 1 , each of the lateral side walls 104 of the vestibule frame 100 include an airflow assembly 120, which will be described in greater detail below with reference to FIGS. 3 and 4 . However, in some embodiments, the vestibule frame may only include a single airflow assembly 120. Each airflow assembly 120 can include an exhaust panel 122 disposed within the vestibule 102 (only one exhaust panel 122 is visible in FIG. 1 , with the opposite exhaust panel of the example embodiment being a mirror image of the exhaust panel 122 shown). Thus, the exhaust panels 122 on the opposing lateral side walls 104 face each other, though only a single exhaust panel 122 is visible in FIG. 1 . However, in other embodiments, a second exhaust panel may include different features or geometries that do not mirror the exhaust panel 122 shown.

Each airflow assembly 120 can further include an exterior frame member 124 disposed on the outside of the vestibule 102. Within each airflow assembly 120, the exhaust panel 122 and the exterior frame member 124 together form a space 126 within the airflow assembly 120. The space 126 may form a portion of an air passage, the air passage also extending into the header 106. The space 126 is in fluid communication with an interior of the header via an opening 128 in the header 106. The space 126 can define a cross section having a similar geometry as the opening 128 (e.g., a rectangular cross section).

In some embodiments, the vestibule 102 can further include a door member or flexible barrier 130 across one or both of the openings 112. For example, the flexible barrier 130 can be configured as a strip curtain configured to reduce airflow between the temperature zones (e.g., to help keep a refrigerated or freezer zone cool). In some embodiments, the vestibule 102 can include a first flexible barrier 130 at one opening 112, and a second flexible barrier (not shown) at the second opening, such that the vestibule 102 defines a volume interiorly enclosed by the lateral side walls 104, the header 106, the ground at the bottom 110 of the vestibule frame 100, and the flexible barriers 130. However, in other embodiments, a single flexible barrier 130 may be positioned at one of the two openings 112, either adjacent to the warm zone or the cold zone.

In other embodiments, the flexible barrier 130 can be configured as any movable door across one or both of the openings 112, including swinging doors, sliding doors, suspended doors, automatic doors, etc., and combinations thereof. Additionally, the flexibility of the flexible barrier 130 may relate to the flexibility or option of the openings 112 of the vestibule 102 to be covered. Thus, in some embodiments, the flexible barrier 130 may comprise a rigid material. Further still, in other embodiments the vestibule 102 may not incorporate any barriers (e.g., flexible barrier 130).

With reference to FIG. 2 , the vestibule 102 can further include one or more blowers 136 or air handling units. The blowers 136 may be positioned at the top 108 of the vestibule frame 100 within the header 106. However, other configurations are possible, such as, for example, one or more blowers positioned at the bottom 110 of the vestibule frame 100. In the illustrated configuration, the one or more blowers include first and second blowers 136 laterally spaced within the header 106 so that one blower 136 is adjacent to one airflow assembly 120 at one lateral side wall 104, and the other blower 136 is adjacent to the other airflow assembly 120 at the other lateral side wall 104.

As briefly described above, an air passage extends into the space 126 of each of the airflow assemblies 120 and into the header 106 at the openings 128. In particular, the air passage can be in fluid communication with an outlet 138 of the associated blower 136. As a result, in use, as the blower 136 blows air, air can travel along the air passage from the header 106 to the airflow assemblies 120. As air flows into the space 126 of each airflow assembly 120, the exhaust panels 122 can distribute (e.g., diffuse) air into the vestibule 102 via exhaust ports 146 (see, for example, FIGS. 3 and 4 ) arranged in a progressive ventilation pattern. In some embodiments, the air distributed into the vestibule 102 via the exhaust ports 146 can establish an air curtain generally between the airflow assemblies 120.

With reference to FIGS. 3 and 4 , the airflow assembly 120 can include one or more mounting brackets 148 configured to secure the exhaust panel 122 relative to the exterior frame member 124. In the illustrated embodiment, a top mounting bracket 148 a may be disposed near the top 108 of the vestibule frame 100 and a center mounting bracket 148 b may be disposed between the top 108 and the bottom 110 of the vestibule frame 100. Additionally, a bottom plate 150 may be disposed near the bottom 110 of the vestibule frame 100 and configured to further secure the exhaust panel 122 relative to the exterior frame member 124. Additionally, the bottom plate 150 may act as a cap to the space 126 within the airflow assembly 120.

The airflow assembly 120 can further include an open top bracket 152 dimensioned to surround at least a portion of a top perimeter of the space 126 and help secure the lateral side wall 104, and thus the airflow assembly 120, relative to the header 106. The open top bracket 152 can define an opening 154 and have a similar profile to the exterior frame member 124 so that the air passage can pass through the header 106 at the opening 128 and into the space 126 within the airflow assembly 120. In other embodiments, an open top bracket may completely surround a top of the exterior frame member 124 while still providing an opening (similar to the opening 154) therethrough so that airflow from the blower 136 can reach the space 126 within the airflow assembly 120.

In other embodiments, a space formed within the lateral side walls 104 may be formed by the exhaust panel 122 and another member of the airflow assembly 120 (not shown) such that the volume of the space 126 is not bounded by the exterior frame member 124, but rather another panel member, thereby decreasing the volume of the space 126 promoting faster airflow.

With continued reference to FIGS. 3 and 4 , the exhaust panel 122 defines a plurality of exhaust ports 146. In the illustrated embodiment, the plurality of exhaust ports 146 are arranged as an array of exhaust ports 146. In particular, in the illustrated embodiment, the array of exhaust ports 146 increase in density (i.e., amount) across the vertical height of the exhaust panel 122 from top (i.e., adjacent to the top 108 of the vestibule frame 100) to bottom (i.e., adjacent to the bottom 110 of the vestibule frame 100).

With reference to FIG. 4 , the array of exhaust ports 146 may be split into sections based on the density of exhaust ports 146 extending laterally across the exhaust panel 122. For example, in the illustrated embodiment, the exhaust panel 122 may be split into five sections (e.g., I, II, III, IV, and V). Each section can include a plurality of exhaust ports 146. The plurality of exhaust ports 146 can be arranged in a horizontal row with one or more exhaust ports 146 in each row. Additionally, each section can include varying numbers of horizontal rows of exhaust ports 146.

In the embodiment shown, section I is positioned near the top of the airflow assembly 120 and includes single exhaust ports 146 per horizontal row extending in the lateral direction across the exhaust panel 122. Section II is positioned below section I and includes 1 to 2 exhaust ports 146 per horizontal row extending in the lateral direction across the exhaust panel 122. Section III is positioned below section II and includes 2 to 3 exhaust ports 146 per horizontal row extending in the lateral direction. Section IV is positioned below section III and includes 3 to 4 exhaust ports 146 per horizontal row extending in the lateral direction. And section V is positioned below section IV and includes 4 to 5 exhaust ports 146 per horizontal row extending in the lateral direction.

In the illustrated embodiment, the exhaust ports 146 are disposed within a tapered periphery 166. The tapered periphery 166 can define a top 168 adjacent to the top 108 of the vestibule frame 100, and a bottom 170 adjacent to a bottom 110 of the vestibule frame 100. Furthermore, the tapered periphery can include lateral sides 172. The lateral sides 172 can be non-parallel to define the tapered geometry. In the illustrated embodiment, the tapered periphery 166 can define a trapezoid, with the top 168 defining the smaller or narrowed side and the bottom 170 defining the larger or wider side. However, other geometries are possible, such as a triangle for example, such that the top 168 forms a point of the triangle.

In general, as the sections progress (e.g., downwardly), the density or effective flow openings of the exhaust ports increases. This can allow more air to flow from the airflow assembly 120 into the vestibule 102 near the bottom 110 of the vestibule frame 100 compared to near the top 108. However, it should be appreciated that the configuration of exhaust ports 146 illustrated in FIGS. 3 and 4 may be varied to achieve a similar airflow effect. For example, in other embodiments, each section may include an average of n+1 exhaust ports per row, where n is the number of exhaust ports in the preceding (e.g., above) section. In other embodiments, the total number of exhaust ports per section may increase (e.g., linearly or parabolically) from top to bottom of the exhaust panel, the exhaust ports not necessarily organized by row.

In other embodiments, the exhaust ports need not be generally similar in size and/or shape, such that the desired gradient increase in air flow capacity to provide progressive ventilation along the length of the exhaust panel(s) is achieved by altering the size and/or shape of the available air flow path through the one or more exhaust ports in the exhaust panel. Further, the exhaust panel may define a single continuous exhaust port having an exhaust port that defines an increasing air flow capacity from an upper end toward a lower end of the exhaust port (e.g., an exhaust port defining opposing opening walls that diverge from the top toward the bottom of the exhaust port).

Additionally, while the exhaust ports 146 in the illustrated embodiment define an oval-like geometry, other geometries are possible. For example, some embodiments can include exhaust ports having geometries that are circular, conical, polygonal, irregular, slotted, elongated, etc. Further, in some embodiments, the profiles or geometries of exhaust ports may vary along an exhaust panel. For example, in some embodiments, certain exhaust ports near the bottom of a vestibule frame may be conical (e.g., nozzle-shaped) to increase airflow near the ground of the vestibule. Given the benefit of this disclosure, one skilled in the art will appreciate the various modifications that can be made to the exhaust port(s) to achieve a flow capacity gradient to address particular application-specific variables and requirements (e.g., vestibule dimensions, temperature gradient between zones, etc.).

In one embodiment, the airflow gradient established by and expelled from the exhaust port(s) is substantially uniform or even along the height of the exhaust panel(s) (e.g., by accounting for application-specific upstream air losses and the particular distance from the air handler). In still further embodiments, the exhaust ports can be configured to establish an airflow gradient configuration that widens (e.g., in the direction extending between the openings 112), or increases in flow capacity, toward the bottom of the vestibule to account for and, in some embodiments, balance the influence (e.g., volume, flow rate, density) of increasingly cooler air near the bottom of the vestibule relative to the warmer air near the top of the vestibule. The particular gradient can also be configured to direct additional relatively warmer air (e.g., more warmer air than necessary to account for the cooler air) toward the floor supporting the vestibule to further inhibit the formation of undesirable surface conditions. Given the benefit of this disclosure, one skilled in the art will appreciate the various vestibule exhaust configurations that can be established to achieve particular application-specific vestibule design parameters using the principles of the present disclosure.

Referring now to FIGS. 5-7 , the header 106 can include one or more blowers 136 positioned at opposing ends of the header 106, generally above each of the first and second lateral side walls 104. The blowers 136 can include heating elements (or may generally be configured as heaters) so that they can blow hot air (relative to the cold zone, for example) out of their respective outlets 138. A corresponding air intake of the blowers 136 may be in fluid communication with an interior of the header 106, which can include a header intake 158. The header intake 158 may be in fluid communication with the vestibule 102 and can draw cool air (relative to the warm zone, for example) from the vestibule 102 that may then be heated via the blowers 136 and dispersed along the fluid passage into the airflow assemblies 120.

With reference to FIG. 7 , the header 106 may be generally configured as a header assembly 160 and can include the blowers 136 and a plurality of mounting and fastening members. For example, the header assembly 160 can include blower mount plates 162 configured to secure the blowers 136 relative to the header 106. In the illustrated embodiment, the blower mount plates 162 are configured as brackets that can be mounted at an angle relative to the lateral sides of the header 106 to orient that outlets 138 of the blowers 136 relative to the corresponding airflow assemblies 120 so that forced air (heated above 0 degrees Celsius) from the blower 136 can be directed through the exhaust panel 122 and distributed into the vestibule 102. The heated air exiting the exhaust ports 146 of the exhaust panel 122 can reduce or eliminate frost or ice buildup within the vestibule frame 100.

In some implementations, devices or systems disclosed herein can be utilized, manufactured, or installed using methods embodying aspects of the invention. Correspondingly, any description herein of particular features, capabilities, or intended purposes of a device or system is generally intended to include disclosure of a method of using such devices for the intended purposes, a method of otherwise implementing such capabilities, a method of manufacturing relevant components of such a device or system (or the device or system as a whole), and a method of installing disclosed (or otherwise known) components to support such purposes or capabilities. Similarly, unless otherwise indicated or limited, discussion herein of any method of manufacturing or using for a particular device or system, including installing the device or system, is intended to inherently include disclosure, as embodiments of the invention, of the utilized features and implemented capabilities of such device or system.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Given the benefit of this disclosure, various modifications to these embodiments will be readily apparent to those skilled in the art, and the principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. 

1. A conditioned air vestibule configured to be positioned between a first zone and a second zone, the vestibule comprising: a frame having first and second lateral side walls; a header positioned at a top of the frame and extending between the first and second lateral side walls; a blower having a blower outlet; an airflow assembly having an exhaust panel with a plurality of exhaust ports, the plurality of exhaust ports in fluid communication with an interior of the frame and increasing in flow capacity along a length of the exhaust panel from proximate the top of the frame toward a bottom of the frame; and an air passage in fluid communication with the blower outlet and the airflow assembly.
 2. The conditioned air vestibule of claim 1, wherein the plurality of exhaust ports are arranged within a tapered periphery, the tapered periphery defining a narrowed end adjacent to the top of the frame and a wide end adjacent to the bottom of the frame.
 3. The conditioned air vestibule of claim 1, wherein the airflow assembly is a first airflow assembly, and the conditioned air vestibule further comprises a second airflow assembly.
 4. The conditioned air vestibule of claim 3, wherein the second airflow assembly includes a plurality of exhaust ports arranged in a different geometry than the first airflow assembly.
 5. The conditioned air vestibule of claim 1, wherein the airflow assembly forms at least one of the first and second lateral side walls.
 6. The conditioned air vestibule of claim 1, wherein the blower is housed within the header and configured to provide heated forced air flow through the exhaust ports.
 7. The conditioned air vestibule of claim 6, wherein the header includes an air intake in fluid communication with the blower.
 8. The conditioned air vestibule of claim 7, wherein the air intake is in fluid communication with an interior of the vestibule.
 9. The conditioned air vestibule of claim 1, wherein the air passage is in fluid communication with the header.
 10. The conditioned air vestibule of claim 1, wherein the flow capacity of the exhaust ports increases linearly.
 11. The conditioned air vestibule of claim 1, wherein the plurality of exhaust ports define geometries that vary along the length of the exhaust panel.
 12. The conditioned air vestibule of claim 11, wherein certain exhaust ports of the plurality of exhaust ports nearer to the bottom of the frame are conical.
 13. The conditioned air vestibule of claim 1, wherein a density of the plurality of exhaust ports increases in discrete zones defined between the top and the bottom of the frame.
 14. An airflow assembly for a conditioned air vestibule, the airflow assembly comprising: an exterior frame member; a bottom plate; an exhaust panel configured to be secured relative to the exterior frame member; and an air passage formed between the exterior frame member, the bottom plate, and the exhaust panel, the exhaust panel including an exhaust port structured to provide increasing fluid communication along the exhaust panel between the air passage and an interior of the conditioned air vestibule.
 15. The airflow assembly of claim 14, further comprising a top bracket opposite the exterior frame member from the bottom plate and configured to be secured to a header of the airflow assembly, the top bracket defining an opening in fluid communication with the air passage.
 16. The airflow assembly of claim 14, wherein the exhaust port comprises a plurality of exhaust ports arranged in a progressive ventilation pattern to provide an airflow gradient along the exhaust panel.
 17. The airflow assembly of claim 16, further comprising a blower in fluid communication with the air passage and configured to provide forced air through the air passage, and wherein the blower is in fluid communication with an air intake disposed at a top of the conditioned air vestibule.
 18. The airflow assembly of claim 14, wherein the exhaust port comprises a plurality of exhaust ports disposed within a tapered periphery, the tapered periphery defining a narrowed end adjacent to a top of the of the conditioned air vestibule and a wide end adjacent to a bottom of the conditioned air vestibule.
 19. A method of conditioning air in a vestibule positioned between first and second zones capable of different ambient conditions, the method comprising: intaking air from an interior of the vestibule into a header of the vestibule; conditioning the air; forcing the conditioned air through an air passageway; and exhausting the conditioned air through an exhaust port formed in an exhaust panel and in fluid communication with the air passageway, the exhaust port defines an increasing air flow capacity from an upper end toward a lower end.
 20. The method of claim 19, wherein the exhaust port comprises multiple exhaust ports arranged in a progressive ventilation pattern to provide an air flow gradient to the interior of the vestibule so that a higher volume of air is exhausted through the multiple exhaust ports closer to a bottom of the vestibule than a top of the vestibule. 